TIMING RESULTS ON FIVE HIGH-GRADE WATCHES

BY WALT ODETS

Much has been made–perhaps too much–about the “accuracy” of mechanical watches. There are very few of us who actually rely on a watch to be accurate to within a second or two a day. For my personal use, a watch that is conveniently accurate–that need only be reset every week or two to fall within the correct minute–is more than enough. Yet, the enthusiast-owners of many mechanical watches regularly check their watches for accuracy of daily rate. And, to some extent, the running regularity of a watch expresses the craft that went into construction and adjustment of the escapement.

The simple check of daily rate is, in fact, an observation of multiple errors that both exacerbate and cancel each other. Most watches of quality can be adjusted to provide good rate for a particular owner of consistent habits. One simply adjusts the daily rate with the regulation device until the complex errors provide a favorable interaction. The real measure of escapement construction and craft is the performance between different positions. Close performance between horizontal (dial-up and dial-down) and vertical (crown-down, crown-left, and crown-up) positions is very much more difficult to achieve than simple accuracy of daily rate.

The following five timing charts were all performed on the morning of November 27, 1999 on five watches in my possession at the time. These include a Chopard 16-1860, a Lange Sax-O-Mat, a Lange Saxonia, a Patek 5035, and a Patek 5055. All, save the Patek 5055, had been purchased new within the last 18 months. The Patek 5055 was purchased as a used watch. None of these watches have received service since purchase, save the Lange Saxonia, which was serviced by me within the month. With the exception of the Saxonia, none has received adjustment of daily rate (accomplished during service).

I will discuss each chart separately. A few concepts should be remembered in reviewing the charts.

Absolute

deviation from daily rate can easily be corrected in any of these high-grade watches. The most important issue in judging the quality and adjustment of the escapement is performance between positions.

Dial-up and dial-down performance should be close. Any difference between these two horizontal positions reflects errors in adjustment of the regulator on those watches so equipped (the Langes and Chopard); defects in the upper or lower balance pivot; lubrication differences between the upper and lower pivot; or an out-of-flat condition of the balance spring which is causing it to rub on the plate or (more usually) on the underside of the balance cock.

The typical user wearing the watch on the outside of the left wrist will find the close adjustment of dial-up and crown-down positions to be the most useful single indicator of good daily rate in use.

Crown-left will be the next most significant position, followed by crown-up, which is little used in daily wear.

The user wearing a watch on the inside of either wrist will find crown-right of more significance than crown-left.

The user wearing a watch on the inside of the right wrist will find crown-up more important than crown-down.

I have rated the watches according to the above criteria, and each is discussed in order from worst to best performance. It should be said emphatically that any model of watch will vary from sample to sample, and each sample often varies from time to time. Individual watches may also contain defects that affect performance, though none of the tested watches, excepting the Patek 5055, showed apparent defects.

THE LANGE SAX-O-MAT (5)

This automatic-winding watch uses a flat Nivarox 1 spring with Glucydur balance wheel. The laser-poised wheel wheel is equipped with nonfunctional screws which, however, contained a washer under each of two opposing screws. Because the simple Lange design does not permit centering the regulator index without adjusting the regulator itself, these two screws were probably added to slow the movement and allow centering of the regulator index (for cosmetic reasons) at the time of sale.

Beat error (< .6 milliseconds) and amplitude (270-320 degrees in horizontal positions) fall within a normal range. The four second variation between dial-up and dial-down positions is within reasonable tolerances.

performance varied 15 seconds from the dial-up, a very poor performance for a high-grade watch.

THE LANGE SAXONIA (4)

The Saxonia uses an escapement identical to that of the Sax-O-Mat: a flat Nivarox 1 spring and Glucydur balance. Like the Sax-O-Mat, this Saxonia carried two timing washers on an opposing pair of screws.

Beat and amplitude fall within a normal range. The Saxonia very slightly edges the Patek 5055 out of fourth place because of the eight (as opposed to seven) second variation between dial-up and crown-down positions. This figure is a bit high for a high-grade watch adjusted to three or more positions. Otherwise, the performance of the Saxonia is exemplary and within reasonable adjustment limits (a common standard of six seconds maximum difference between positions) for a high-grade watch.

THE PATEK 5055 (3)

The Patek caliber 240-164 is a micro-rotor automatic winding movement with a flat Nivarox I balance spring and Glucydur balance in the Gyromax (adjustable inertia) design. This is a free-spring design (no regulator is used). Daily rate is adjusted with the Gyromax rim weights.

Beat error and amplitude fall within normal range. The Patek falls to third position largely because of the relatively high dial-up rate and a consequent variation between dial-up and crown-down of seven seconds. The spread between dial-up and dial-down positions is too large (11 seconds), particularly for a watch without a regulator. This spread suggests a probable mechanical or lubrication defect. (This is the only used watch of unknown service history in the test.) Were this deviation to be corrected through repair or re-lubrication, the performance of this watch would be considerably improved.

THE PATEK 5035 (2)

The Patek 5035 utilizes a caliber 315 movement with centrally-mounted rotor for automatic winding. The escapement is similar to that of the caliber 240, utilizing a Nivarox 1 balance spring and Glucydur Gyromax balance wheel.

Beat Error and amplitude are within normal range. The one second variation between dial-up and crown-down positions is an excellent performance. The largest variation between positions (six seconds) falls between the crown-down and crown-left positions, a good performance for a high-grade watch.

THE CHOPARD 16-1860

The Chopard caliber 1.96 is a micro-rotor equipped automatic winding watch equipped with a Nivarox 1 balance spring and smooth Glucydur balance. Unlike the other four watches in this test, the Chopard is equipped with a balance spring overcoil.

Beat error and amplitude fall within a normal range. Noteworthy, however, is the close tolerance between amplitude in all five positions.

Positional performance is absolutely exemplary. The one second deviation between dial-up and crown-down positions speaks of the overcoil spring. Maximum variation between positions (six seconds) falls between the dial-up and relatively unimportant crown-up position. Ideally, a regulator would like to place the most extreme variation in the least significant position. An adjustment of daily rate with the extremely well-designed micro-screw regulator would make the Chopard a remarkable daily performer.

CONCLUSIONS

One is always reluctant to extrapolate from individual samples to groups about something as quirky and variable as the adjustment of a mechanical watch. In this sample of five, however, there are some clear trends, and these trends concisely reflect the conceptual quality of the escapements in question. The Lange watches utilize a currently ubiquitous and pedestrian escapement, combining a plain balance (with cosmetic screws) and flat spring. The Pateks benefit from the Gyromax design and lack of a regulator. Such a free-sprung design is very likely, over time, to prove the most consistent performer. Finally, the Chopard with its overcoil provides positional performance unobtainable with a flat spring. The Chopard regulator is extremely well made and immaculately adjusted, but, if disturbed by carelessness during service, it has the potential to introduce degrading positional errors.

The importance of fine positional adjustment in a mechanical watch is of only moderate significance to those consistent users seeking nothing more than stable daily rate. If craft is an issue, however, there is nothing quite like a finely adjusted mechanical watch.